Tag Archives: bioelectricity

Why DNA is like a phone cable (Recap of a Talk by Prof. Jacqueline Barton)

[Computer rendering of DNA. Via Caroline Davis2010 on Flickr & CC 2.0] 

The Talk:

“DNA-mediated Signaling with Metalloproteins”

In Plain English:

DNA can conduct electricity–like metal wire–and that helps the cell life

The Speaker:

Jacqueline Barton of Caltech

The Sponsor:

MIT Inorganic Chemistry (invited by the grad students)

What It Covered:

When Jacqueline Barton’s lab began publishing papers claiming that DNA can conduct electricity, many of her colleagues didn’t believe them. But in experiment after experiment, they kept finding that they could send small amounts of electricity–much lower than the amount that flows through your charger cord–from an electrode on one end of a DNA strand through to the other.

The exceptions were stretches of DNA with “missense mutations“, hiccups in the genetic code that violated the rule of “G” aligns with “C” and “A” aligns with “T”.

A,T, G, and C are biologists’ shorthand for four small molecular structures– adenine, thymine, guanine, and cytosine– that repeat over and over again along DNA’s backbone. It just so happens that a G-C pair takes up exactly the same amount of space and adds exactly the same amount of twist as an A-T pair.  Anything else–a misplaced guanine, a broken cytosine, or a chemical tag on thymine– throws the DNA’s twist out of whack. And apparently,  the missense mutations also blocked electrical currents’ flow through a tiny gap in the center of the DNA.  Mismatched base pairs or base pairs that were even slightly damaged blocked the electrons’ path. Continue reading “Why DNA is like a phone cable (Recap of a Talk by Prof. Jacqueline Barton)” »

Stem Cell Science Double Feature: Reprogramming Cardiac Fibroblasts – Recap of talk by Dr. Deepak Srivastava

The Talk:

Cardiac Reprogramming: From Developmental Biology to Regeneration

In Plain English:

How to turn the heart-dwelling cells that build connective tissues into replacements for damaged heart muscle cells

The Speaker:

Dr. Deepak Srivastava, MD of UC-SF‘s Gladstone Institutes

The Sponsor:

MIT Biology Colloquium

What it covered:

Dr. Deepak Srivastava is a cardiologist who experiments with using stem cells to create replacement cells for damaged heart muscle tissue. However, while most labs try to grow replacements in petri dishes, Dr. Srivastava’s lab is working on finding a way to transform the cells that build scar tissue in the heart (the cardiac fibroblasts) into fully functional heart muscle cells.

A typical fibroblast’s job is to secrete collagen and other chemicals that help the cells in muscle and skeletal tissues stick together. If they weren’t there, your muscle cells might slide around or come apart whenever you moved. Luckily, muscle cells like to form stringy structures called sarcomeres that can contract and release. When you’re flexing your muscles, you’re actually contracting the sarcomeres and that contractile force is what causes your arm to tense up. Without the fibroblasts, the muscle cells would have a hard time aligning themselves correctly (and if one cell is even slightly out of line with its neighbor cells, the rogue cell can throw everything off), so they’re a pretty important cell group. Continue reading “Stem Cell Science Double Feature: Reprogramming Cardiac Fibroblasts – Recap of talk by Dr. Deepak Srivastava” »

Bioelectric signals tell organisms when to grow limbs (among other things) – Recap of talk by Dr. Michael Levin

[This post is part of a series called “Brown Bag Lunch Reports” where I recap some of the academic talks given at college campuses in and around the city of Boston. Let me know what you think of the post format and what kinds of talks you think I should recap next!]

The Talk’s Title:

Manipulating natural bioelectric gradients to control growth and form in embryogenesis, regeneration, and cancer

In Plain English:

Changing the ways electric signals flow through living tissues alters the organisms’ growth in profound ways, including (but not limited to) the regeneration of complex organs like eyes and limbs.

The Speaker:

Michael Levin, Ph.d. of the Tufts Center for Regenerative Medicine and Developmental Biology

The Location:

Northeastern University’s Center for Interdisciplinary Research on Complex Systems

What it covered:

Dr. Michael Levin’s lab investigates a little-known (and if half of what he says is true, very underappreciated) topic in biology: the effect of variation in the electric charges of cells on morphological development. If that last sentence sounded like a random string of sciencey-sounding words from different disciplines, there’s a reason for that: Dr. Levin’s work draws heavily from both physics and molecular biology. Continue reading “Bioelectric signals tell organisms when to grow limbs (among other things) – Recap of talk by Dr. Michael Levin” »